Recently, as FDA as EMEA provides recommendations to sponsors concerning the design, conduct, analysis and interpretation of clinical studies to assess the potential for delaying cardiac repolarisation. This paper recommends to perform a ‘through Qt/QTc’ study to expand ECGs safety evaluation during later stages of drug development. It was recomended that the study was randomized, blind and placebo controlled. Moreover, as a high sensitivy is necessary in order to detect differences in the QTc measure, it was essential a positive control included. On that basis, the positive control should be well-characterized and consistently produce an effect corresponding to the largest change in the QT/QTc interval that is currently viewed as clinically not important to detect (a mean change of around 5 ms. Because of this, we decide select as positive control: moxifloxacin, used in the most of similar phase I clinical trials.